Relationship of Changes in Physical Fitness and Anthropometric Characteristics over One Season, Biological Maturity Status and Injury Risk in Elite Youth Ski Racers: A Prospective Study

Associations between growth, maturation and injury in youth athletes engaged in elite pathways: a scoping review

OBJECTIVE

To describe the evidence pertaining to associations between growth, maturation and injury in elite youth athletes.

DESIGN

Scoping review.

DATA SOURCES

Electronic databases (SPORTDiscus, Embase, PubMed, MEDLINE and Web of Science) searched on 30 May 2023.

ELIGIBILITY CRITERIA

Original studies published since 2000 using quantitative or qualitative designs investigating associations between growth, maturation and injury in elite youth athletes.

RESULTS

From an initial 518 titles, 36 full-text articles were evaluated, of which 30 were eligible for final inclusion. Most studies were quantitative and employed prospective designs. Significant heterogeneity was evident across samples and in the operationalisation and measurement of growth, maturation and injury. Injury incidence and burden generally increased with maturity status, although growth-related injuries peaked during the adolescent growth spurt. More rapid growth in stature and of the lower limbs was associated with greater injury incidence and burden. While maturity timing did not show a clear or consistent association with injury, it may contribute to risk and burden due to variations in maturity status.

CONCLUSION

Evidence suggests that the processes of growth and maturation contribute to injury risk and burden in elite youth athletes, although the nature of the association varies with injury type. More research investigating the main and interactive effects on growth and maturation on injury is warranted, especially in female athletes and across a greater diversity of sports.

We know a lot about little and little about a lot: A contextualized scoping review on injury prevention in alpine ski racing

BACKGROUND

Our goal was to summarize and contextualize the available literature on alpine ski racing injury epidemiology, injury etiology, injury prevention measures, injury prevention context, and implementation issues.

MATERIALS AND METHODS

We searched four electronic databases using predetermined search terms. We included original studies that assessed injury, injury risk factors, and injury mechanisms, and assessed and reported the effect of an injury prevention measure in alpine ski racing. Two authors independently conducted title-abstract screening, and one performed the full-text review. For data synthesis and categorization, we used the Translating Research into the Injury Prevention Practice framework and a modified and adapted version of the Haddon matrix.

RESULTS

Of the 157 included studies, most corresponded to injury epidemiology and etiology, whereas few studies encompassed injury prevention measure development, implementation and evaluation. Preventive interventions targeting equipment, rules and regulations, course design and snow preparation were the most prevalent in the literature. Furthermore, various contextual factors in the current literature have been found, including gender, competition level, countries and federations, and time periods within a season.

CONCLUSIONS

We provided an in-depth and comprehensive overview of the current state-of-the-art in the alpine ski racing context. We know a lot about little and little about a lot across all the areas associated with injury prevention in such context. The limitations in the literature yield a road map for designing future injury prevention studies to address the key gaps identified. A more comprehensive context-driven approach throughout all stages of injury prevention would benefit the ultimate implementation of effective preventive strategies.

Winter Sports Injuries in Elite Female Athletes: A Narrative Review

There is a lack of reviews covering the topic of the parallel high prevalence of injuries in female winter sport elite athletes. We aimed to review the data on incidence and patterns of injuries in female athletes participating in official competitions of winter sports. We conducted a comprehensive literature search on epidemiological data and etiological information on alpine skiing, snowboarding, ski jumping and cross-country skiing. The most common location of injury was the knee among skiers and ski jumpers and the incidence of severe ACL events was 7.6 per 100 ski racers per season (95% CI 6.6 to 8.9) in female alpine skiers. Snowboarders and cross-country skiers were more affected in the ankle and the foot. The most common cause was contact trauma with stagnant objects. The injury risk factors include training volume, knee pre-injuries, the period of the season and the technical equipment. Females are at greater risk of suffering from overuse injuries during the competitive season, as opposed to male athletes who are more likely to suffer from traumatic injuries. Our findings can be used to inform coaches and athletes and to guide future injury prevention plans.

The impact of sport-specific physical fitness change patterns on lower limb non-contact injury risk in youth female basketball players: a pilot study based on field testing and machine learning

Background: In recent years, identifying players with injury risk through physical fitness assessment has become a hot topic in sports science research. Although practitioners have conducted many studies on the relationship between physical fitness and the likelihood of injury, the relationship between the two remains indeterminate. Consequently, this study utilized machine learning to preliminary investigate the relationship between individual physical fitness tests and injury risk, aiming to identify whether patterns of physical fitness change have an impact on injury risk. Methods: This study conducted a retrospective analysis by extracting the records of 17 young female basketball players from the sport-specific physical fitness monitoring and injury registration database in Fujian Province. Sports-specific physical fitness tests included physical performance, physiological, biochemical, and subjective perceived responses. The data for each player was standardized individually using Z-scores. Synthetic minority over-sampling techniques and edited nearest neighbor algorithms were used to sample the training set to address the negative impact of class imbalance on model performance. Feature extraction was performed on the dataset using linear discriminant analysis, and the prediction model was constructed using the cost-sensitive neural network. Results: The 10 replicate 5-fold stratified cross-validation showed that the lower limb non-contact injury prediction model based on the cost-sensitive neural network had achieved good discrimination and calibration (average Precision: 0.6360; average Recall: 0.8700; average F2-Score: 0.7980; average AUC: 0.8590; average Brier-score: 0.1020), which could be well applied in training practice. According to the attribution analysis, agility and speed were important physical attributes that affect youth female basketball players' non-contact lower limb injury risk. Specifically, there was enhance in the performance of the 1-min double under, accompanied by an increase in urinary ketone and urinary blood levels following the agility test. The 3/4 basketball court sprint performance improved, while urinary protein and RPE levels decreased after the speed test. Conclusion: The sport-specific physical fitness change pattern can impact the lower limb non-contact injury risk of young female basketball players in Fujian Province, specifically in terms of agility and speed. These findings will provide valuable insights for planning athletes' physical training programs, managing fatigue, and preventing injuries.

Growth until Peak Height Velocity Occurs Rapidly in Early Maturing Adolescent Boys

The timing and tempo of growth rate varies inter-individually during adolescence and can have an impact on athletic performance. This study aimed to determine the difference in growth rate for each maturity status. We combined data collected both retrospectively and prospectively from 78 adolescent boys aged 12 years old; growth charts were collected from their elementary school records, and the height of each participant was subsequently measured every six months over a period of two years. Take Off Age (TOA), Peak Height Velocity Age (PHVA), and Final Height Age (FHA) were estimated using the AUXAL 3.1 program. Growth Tempo 1 and 2 were calculated by dividing the height increase by the time difference between TOA and PHVA, and FHA, respectively. Our results showed three group differences based on the maturation status of PHVA: Growth Tempo 1 and 2 were both higher in the early than during middle and late maturation. Additionally, entering the height at each event as a covariate, the group differences for Growth Tempo 1 did not change; however, for Growth Tempo 2, group differences were eliminated. Therefore, we conclude that during early maturation, growth from TOA to PHVA occurs rapidly and in a shorter period.

Relationship between Lower Extremity Fitness Levels and Injury Risk among Recreational Alpine Skiers: A Prospective Cohort Study

Background: Although the importance of physical fitness for injury prevention is recognized in sports medicine and rehabilitation, few studies have investigated this factor among recreational alpine skiers. Objective: To determine the effect of lower extremity fitness on the risk and severity of injury among recreational alpine skiers. Method: This prospective cohort study involved 117 recreational skiers at two alpine resorts during the 2021−2022 winter season. Anthropometric characteristics, skiing skills, and lower extremity agility (hexagon test), balance (Y-Balance Test), and endurance (60-s squat test) were assessed before the winter season. All of the participants were divided into an injured group and an uninjured group, based on whether an injury was recorded throughout the season. Results: In binary logistic regression, the hexagon test duration and composite Y-Balance Test score were significant injury risk factors (p < 0.05). Ordinal polytomous logistic regression revealed no significant factors for injury severity (p > 0.05). Conclusions: Recreational alpine skiers with inferior lower extremity agility or balance may have a higher injury risk and this must be considered when assessing individual risk. In the context of injury prevention, regular neuromuscular training and testing, including agility and balance aspects should be recommended to skiers.

Incidence of injuries in professional snow sports: A systematic review and meta-analysis

PURPOSE

The study aimed to conduct a comprehensive systematic review and meta-analysis of injury incidence in professional skiers and snowboarders.

METHODS

We systematically searched PubMed, Web of Science, and MEDLINE for studies on injury incidence published from inception to April 2020. Injury data were extracted, alongside information on injury location, severity, type, cause, and sport discipline. Incidence of injuries was presented per 1000 athlete-days, with 95% confidence intervals (95%CIs).

RESULTS

The search identified 462 articles, and 22 were included in our review. The overall incidence of injuries among professional skiers and snowboarders was 3.49 per 1000 athlete-days (95%CI: 2.97-4.01). Lower extremity had the highest injury incidence (1.54 per 1000 athlete-days, 95%CI: 1.24-1.84). Incidence rates of slight, mild, moderate, and severe injuries were 0.26, 0.31, 0.57, and 0.59 per 1000 athlete-days, respectively. Contusion had the highest incidence rate (1.82 per 1000 athlete-days, 95%CI: 1.01-2.63). The most common cause of injury was contact trauma (3.20 per 1000 athlete-days, 95%CI: 1.32-5.08). Freestyle skiing had the highest incidence rate (6.83 per 1000 athlete-days, 95%CI: 4.00-9.66), and Nordic skiing had the lowest rate (2.70 per 1000 athlete-days, 95%CI: 1.94-3.46).

CONCLUSION

Professional skiers and snowboarders have a substantial risk of sustaining injuries. Our findings can be used to inform the planning and provision of healthcare for elite participants in different snow sports.

Perceptions of experts on key injury risk factors in alpine ski racing as a function of stakeholder role and associated level of competition

Objectives

(1) To update experts' priorities of perceived key injury risk factors in alpine ski racing based on a framework and list derived 10 years ago, (2) to identify additionally emerging risk factors since then and (3) to compile a list with countermeasure suggestions.

Methods

A sample of 532 expert stakeholders (athletes, coaches, team medical staff, Ski Racing Suppliers (SRS) and International Ski Federation (FIS) representatives) from the World Cup (WC), European Cup (EC) and FIS-race level participated in a cross-sectional online survey. Experts were asked to name those risk factors with the highest believed impact on injury risk and rank them according to their current priority from a predefined list. In addition, experts were encouraged to name additional (not listed) risk factors and to suggest countermeasures.

Results

Regardless of stakeholder role and competition level, snow-related factors appeared to have the highest perceived priority. However, WC athletes' and coaches' perceptions were also related to equipment, while at the EC and FIS-race level fatigue and physical fitness-related factors were considered important. Athletes' perceptions were largely in agreement with SRS (ie, snow-related and equipment-related factors). At the same time, while coaches, team medical staff and FIS representatives additionally emphasised fatigue and physical fitness-related factors.

Conclusion

Experts' perceptions on key injury risk factors in alpine ski racing depend on the stakeholder role and differ between the competition levels. Thus, to develop effective prevention measures and to successfully implement them, all relevant stakeholders should be given a voice, and prevention efforts should be targeted to the specific level.

Hydration Status in Adolescent Alpine Skiers During a Training Camp

Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm³with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm³). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

Influence of Size and Maturity on Injury in Young Elite Soccer Players

The involvement of pre-adolescents in soccer is becoming more and more frequent, and this growing participation generates some concerns about the potential factors for sports injuries. The purpose of this study was to investigate sports injuries in younger (U9–U11) and older (U12–U13) children playing soccer at an elite level, analyzing potential anthropometric and maturity risk factors. A total of 88 elite soccer players aged 9–13 years were investigated. Weight, stature, and sitting height were measured at the start and at the end of the competitive season, computing the relative growth velocities. Additional body composition parameters were taken during a second survey. Maturity offset was calculated using predictive equations based on anthropometric traits such as years from age at peak height velocity (YPHV). Injuries suffered during the competitive season were recorded. Maturity and some anthropometric characteristics were significantly different according to the presence or absence of injuries among the players. Multiple logistic regression revealed that YPHV, body mass index (BMI), and calf muscle area were the factors most significantly correlated with injuries. Players with increased BMI, with decreased calf muscle area, and who were closer to their peak height velocity, were at a higher risk of injury. Findings showed that a monitoring program of anthropometric characteristics taking into account the maturational stage needs to be developed to prevent injuries.

Editorial on the Special Issue on "Mountain Sports Activities: Injuries and Prevention"

Recreational outdoor activities like mountain sports are gaining large popularity all over the world and particularly in the Alpine regions [...].

The relationship between physical fitness attributes and sports injury in female, team ball sport players: a systematic review

BACKGROUND

Understanding the relationships between physical fitness characteristics and sports injury may assist with the development of injury minimisation programs. The purpose of this systematic review was to investigate the association between physical fitness attributes and sports injury in female, team ball sport players.

METHODS

Four scientific databases (MEDLINE, EMBASE, SPORTDiscus, Scopus) and reference lists of relevant research were searched for eligible studies up to September 2, 2019. Full-text articles examining the relationship between physical fitness and sports injury in female, team ball sport players were included. A modified Downs and Black checklist was used to assess methodological quality. Data synthesis determined summary conclusions based on the number of significant relationships divided by the total relationships investigated and reported as a percentage. Level of certainty was identified for summary conclusions based on level of evidence. Sub-analyses regarding competition level, age, and single injury types were also conducted.

RESULTS

A total of 44 studies were included. Data synthesis revealed no associations (low to moderate certainty) between body composition (1/9; 11%), flexibility (18-20%), and balance (2/8; 25%) and 'any injury' classification. No associations (mostly of moderate certainty) were found between flexibility (0-27%), muscular strength (0-27%), and body composition (14-33%) and various body region injury classifications, whereas mixed summary conclusions were shown for balance (0-48%). Many associations between physical fitness and sports injury were deemed 'unknown' or with an insufficient level of certainty. Sub-analyses revealed no association between strength and noncontact ACL injuries (0/5; 0%) or ankle sprains (0/12; 0%), and between flexibility and ankle sprains (1/5; 20%); however, insufficient certainty of these results exists. Clear associations were concluded between balance and lower body injuries in female, non-elite (10/16; 63%) and junior (9/12; 75%) team ball sport players, with moderate and insufficient certainty of these results, respectively.

CONCLUSION

Limited evidence is available to demonstrate relationships between physical fitness and sports injury in female, team ball sport players. High-quality evidence investigating the multifactorial nature of sports injury, including the interactions physical fitness qualities have with other injury determinants, is needed to better understand the role of physical fitness in minimising sports injuries in female, team ball sport players.

TRIAL REGISTRATION

CRD42017077374 (PROSPERO on September 14, 2017).